Seventy-five years ago this week, the world was on the brink of war. It was a very different place: No Twitter, no Facebook, no computers. Not even television. Germany was on the march and Americans were gathered around the radio, listening for bulletins from Europe.

So on Halloween Eve, it must have been unnerving for the millions who tuned into CBS Radio, the respected news source of the day, to hear dance music suddenly interrupted by a chilling series of bulletins:

The Mount Jennings Observatory, Chicago, Illinois reports observing several explosions of incandescent gas, occurring at regular intervals on the planet Mars. The spectroscope indicates the gas to be hydrogen and moving toward the Earth with enormous velocity.

A huge, flaming object believed to be a meteorite fell on a farm in the neighborhood of Grover’s Mill, New Jersey.

Memories of an Actual Disaster

Still fresh in people’s minds was the emotional, first-person radio account of the Hindenburg disaster in another New Jersey town, one year earlier. "The humanity!" exclaimed the announcer as the airship was engulfed in flames. "Oh, the humanity!"

Now, in the Halloween-eve broadcast, the reporter interviewed the farm's owner, who described a hissing sound and greenish streak. “Something smacked the ground," he said, "and knocked me clear out of my chair!”

Listeners then heard the clanking sound of a huge piece of falling metal. “Ladies and gentlemen," the reporter declared, "this is the most terrifying thing I have ever witnessed. Wait a minute! Someone’s crawling out of the hollow top…the eyes are black and gleam like a serpent. The mouth is V-shaped with saliva dripping from its rimless lips that seem to quiver and pulsate.”

Soon, the reporter was abruptly cut off in mid-word and the audience heard six seconds of dead air, followed by an announcer saying “Due to circumstances beyond our control, we are unable to continue the broadcast from Grover’s Mill.”

“It was a perfect storm,” says Heyer, an adviser to PBS’s American Experience: War of the Worlds and a professor of communications studies at Canada’s Wilfrid Laurier University. “Late breaking news bulletins were coming in from Europe. One of Welles’ players got the voice of FDR perfectly. The program was what I call radio verité: microphone feedback, signals being lost and all the things you don’t get in a regular radio drama.”

Such techniques, Heyer notes, were unheard of before Welles used them in his show. “Radio, back then, was theatre of the imagination,” he says.

Would Today's Public be Patsies?

These days, Americans like to think of themselves as street-smart, savvy and sophisticated. We’d never be gullible enough to fall for such a hoax in today’s social media age. Right?

You might ask the stockbrokers responsible for panic selling and the plummeting Dow Jones average after they read a false tweet from a hacked AP account earlier this year saying there were two explosions at the White House and that President Obama was injured.

Or you could talk with the folks in New Jersey who received a text alert from Verizon a few years ago warning of a “civil emergency” and telling people to “take shelter now.” (Verizon neglected to label the text as a test.)

How It Could Happen Again

Walter J. Podrazik, curator of the Museum of Broadcast Communications in Chicago, says you shouldn’t assume a War of the Worlds-like panic couldn’t happen today. “On September 11, 2001, the once unimaginable happened," he says. "That opened the door to anything once again being possible, even if once unimaginable.”

Heyer recalls Ghostwatch, the 1992 BBC television production featuring actual BBC reporters doing a supposedly live investigation of a haunted house. It was so scary, there was widespread chaos and a young boy reportedly committed suicide after watching the program.

But Heyer concedes it’s not likely a War of the Worlds-type hoax would last more than a few minutes today, since truth tellers would debunk it through Twitter and Facebook, posting photos from their phones.

Still, Heyer says he could imagine the public falling for a ruse in 2013 if the fictional story centered on something invisible.

“The perfect storm today would be something that was hard to refute immediately, such as germ warfare or poisoning the New York City drinking water," he says. "If that went out on CNN, even if some people said it was a hoax, there’d be hesitancy. It could set a panic that would last one or two hours.”

Incidentally, Heyer suggested to the producers of the PBS American Experience:War of the Worlds documentary that they begin the program with a late-breaking news bulletin. Their response: Thanks, but no thanks.

Now, you can return to your life: surfing the net, tweeting and listening for aliens. Happy Halloween.